Wang, Kui; Lei, Jinhua; Nie, Heran; Shen, Lu; Chen, Peng; Zhou, Guangyuan
Effects of Interconnected Polymer Nanopores Leading to Different Degrees of Confined Polymerization
In this study, different degrees of ethylene-confined polymerization (non-confined, slightly confined, and highly confined) are presented in porous polymer microspheres (PPMs) with an interconnected tri-modal pore structure. First, three catalysts, Cp2ZrCl2, Cp2TiCl2, and TiCl4, are attached to the interface of PPMs to form a nano-confined space for ethylene polymerization. Then…
Crystal Structure of a Tetrameric DNA Fold-Back Quadruplex
Chu, Betty; Zhang, Daoning; Hwang, Wonseok; Paukstelis, Paul J.
DNA can adopt many structures beyond the Watson–Crick duplex. However, the bounds of DNA structural diversity and how these structures might regulate biological processes is only beginning to be understood. Here, we describe the 1.05 Å resolution crystal structure of a DNA oligonucleotide that self-associates to form a non-G-quadruplex fold-back…
Influence of amide-containing side chains on the mechanical properties of diketopyrrolopyrrole-based polymers
Ocheje, Michael U.; Selivanova, Mariia; Zhang, Song; Nguyen, Thi Hai Van; Charron, Brynn P.; Chuang, Ching-Heng; Cheng, Yu-Hsuan; Billet, Blandine; Noori, Suendues; Chiu, Yu-Cheng; Gu, Xiaodan; Rondeau-Gagné, Simon
An efficient strategy to modulate the mechanical properties of conjugated polymers has been developed through the incorporation of amide-containing alkyl chains in diketopyrrolopyrrole-based conjugated polymers. The side-chain engineering performed with hydrogen bonding moieties (up to 20 mol% of amide-containing side-chains) was found to reduce the crystallinity of the conjugated polymers…
Photopolymerization-assisted self-assembly as a strategy to obtain a dispersion of very high aspect ratio nanostructures in a polystyrene matrix
Montoya Rojo, Ú. M.; Riccardi, C. C.; Ninago, M. D.; Ciolino, A. E.; Villar, M. A.; Ceolín, M.; Zucchi, I. A.; Schroeder, W. F.
Very high aspect ratio nano-objects dispersed in a polymer matrix impart a number of desired characteristics to the material, such as barrier properties to the diffusion of small molecules. Commonly, these dispersions are obtained via top-down procedures that require several time-consuming steps of purification, surface modification, and processing. In this…
Robust poly(aryl piperidinium)/N-spirocyclic poly(2,6-dimethyl-1,4-phenyl) for hydroxide-exchange membranes
Chen, Nanjun; Lu, Chuanrui; Li, Yunxi; Long, Chuan; Zhu, Hong
Herein, for realizing the high efficiency and long lifetime of hydroxide exchange membranes (HEMs) for alkaline membrane fuel cell (AMFC) applications, a series of robust poly(biphenyl piperidinium) (PBP)/6-azaspiro undecane (ASU)-functionalized polyphenyl ether (ASU-PPO) membranes were prepared by a crosslinked strategy. Crosslinked PBP-ASU-PPO membrane combines the advantage of PBP and…
Smart release of antimicrobial ZnO nanoplates from a pH-responsive keratin hydrogel
Villanueva, María E.; Cuestas, María L.; Pérez, Claudio J.; Campo Dall′ Orto, Viviana; Copello, Guillermo J.
A smart antibacterial biomaterial based on a keratin hydrogel with pH-dependent behavior and Zinc Oxide nanoplates as biocide agent has been developed. The pH of a chronic wound is basic due to bacterial metabolism. Originally shrank at acid pH, keratin hydrogels swell upon contact with a bacterial contaminated media leading…
Critical Dependence of Molecular Weight on Thermoresponsive Behavior of Diblock Copolymer Worm Gels in Aqueous Solution
Warren, Nicholas J.; Derry, Matthew J.; Mykhaylyk, Oleksandr O.; Lovett, Joseph R.; Ratcliffe, Liam P. D.; Ladmiral, Vincent; Blanazs, Adam; Fielding, Lee A.; Armes, Steven P.
Reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion polymerization of 2-hydroxypropyl methacrylate was used to prepare three poly(glycerol monomethacrylate)x–poly(2-hydroxypropyl methacrylate)y (denoted Gx-Hy or PGMA-PHPMA) diblock copolymers, namely G37-H80, G54-H140, and G71-H200. A master phase diagram was used to select each copolymer composition to ensure that a pure…
Intrinsic Tuning of Poly(styrene–butadiene–styrene)-Based Self-Healing Dielectric Elastomer Actuators with Enhanced Electromechanical Properties
Ellingford, Christopher; Zhang, Runan; Wemyss, Alan M.; Bowen, Christopher; McNally, Tony; Figiel, Łukasz; Wan, Chaoying
The electromechanical properties of a thermoplastic styrene–butadiene–styrene (SBS) dielectric elastomer was intrinsically tuned by chemical grafting with polar organic groups. Methyl thioglycolate (MG) reacted with the butadiene block via a one-step thiol–ene “click” reaction under UV at 25 °C. The MG grafting ratio reached 98.5 mol % (with respect to…
Synthesis and characterization of nanoparticulate silica with organized multimodal porous structure impregnated with 12-phosphotungstic acid for its use in heterogeneous catalysis
Morales, Dolores M.; Frenzel, Romina A.; Romanelli, Gustavo P.; Pizzio, Luis R.
Mesoporous silica (MESSI) nanoparticles with ordered mesoporous frameworks were successfully obtained using the triblock copolymer P123 as the mesoporous template and agar as micropore former. The agar/TEOS ratio influences the specific surface area (SBET) and the micropore area (SMIC). The SBET values increase with the increment of the agar/TEOS ratio…
Low Temperature Electrochemical Deposition of Aluminum in Organic Bases/Thiourea-Based Deep Eutectic Solvents
Wang, Jinfang; Wang, Peng; Wang, Qian; Mou, Hongyu; Cao, Bobo; Yu, Dongkun; Wang, Debao; Zhang, Suojiang; Mu, Tiancheng
In this study, a series of novel quasi-deep eutectic solvents (QDESs) based on organic base and thiourea (TU) and its derivatives were formed. Among them, DBU/TU or methylthiourea (MTU) could be used for the formation of the stable γ-Al2O3 colloid at quite a high concentration (0.6 mol %), which was…